diff --git a/pyproject.toml b/pyproject.toml
index 664d24a4..6e5e19fc 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -11,7 +11,7 @@ requires-python = "~=3.9"
 readme = "README.md"
 license = "MIT"
 dependencies = [
-    "graphviz>=0.13.2,<0.21.0",
+    "graphviz>=0.13.2,<0.22.0",
     "jinja2>=2.10,<4.0",
     "typed-ast>=1.5.5,<2 ; python_version<'3.8'",
 ]